Coherer for wireless signaling.



PATENTED OCT. 20, 1903. T. E. GLARK. COHERER FOR WIRELESS SIGNALING.AlrLIOATION FILED SEPT. 10. 1902.

6 HVVEWTOR.

.V l J m N0 MODEL.

UNITED STATES ?atented October 20, 1903.

PATENT OFFICE.

THOMAS E. CLARK, OF DETROIT, MICHIGAN, ASSIGNOR TO THOMAS E.

CLARK WIRELESS TELEGRAPH-TELEPHONE (10., OF DETROIT, MICHI- GAN, ACORPORATION.

COHERERFOR WIREEESS SIGNALING.

sFEClFICATION forming part of Letters Patent No. 741,767, dated October20, 1903.

Application filed September 10, 1902. Serial No. 122,749. (No model-l Toall whom it may concern:

Be it known that I, THOMAS E. CLARK, a citizen of the United States,residing at Detroit, in the county of Wayne, State of Michigan, haveinvented certain new and useful Improvements in Ooherers for WirelessSignaling; and I do declare the following to be a full, clear, and exactdescription of the inven tion, such as will enable others skilled in theart to which it appertains to make and use the same, reference being hadto the accompanying drawings, and to the figures of reference markedthereon, which form a part of this specification.

This invention relates to a coherer adapted for use in connectionwith asystem of wireless telegraphy and signaling.

The objects of the invention are to provide simple and effective meansfor receiving the impulses or Hertzian waves capable of such adjustmentas to insure the operation of the receiving apparatus by light or feebleimpulses and enabling the reproduction of said impulses in the signalingapparatus, at the same time providing for decoherin'g the coherer aftereach impulse is received.

A further object is to provide means whereby the coherer may be readilydetached without disconnecting any of the circuit-wires and asecondcohererquicklyreplaced in the receiving-jaws, so as to enable anexchange of co'-' herers should one fail to operate or to enable theintroduction into a circuit of a coherer of different adjustment wherethe character of the impulse might require such a change.

The above objects are attained by the association and arrangement ofparts illustrated in the accompanying drawings, in Which- Figure 1 is asectional view through the parts of the coherer separated. Fig. 2 is adiagrammatical view showing the coherer in a receiving-circuit. Fig. 3is a perspective view of the base and contact-jaws in which the cohereris mounted. Fig. 4 is a transverse section through one of the jaws,showinga contact-terrninal of the electrode therein.

Referring to the characters of reference, 1 designates a glass tubeprovided at its ends with hard-rubber or ebony caps 2, which are sealedor cemented on the ends of said tube.

The contact-terminals 3 are provided with threaded ends 4, adapted toscrew into the rubber caps 2, and with longitudinal openings 5 extendingtherethrough, adapted to receive the stems of the electrodes 6 and 7,

respectively, which pass through said contact-terminals and enter theglass tube from opposite directions. Said electrodes may be formed ofany suitable material, but are preferably made of phosphor-bronzeandconfine between their adjacent faces within the glass tube themetallic filings 8. The stem 9 of electrode 6 is threaded to enable itto be screwed through its contact-terminal 5, whereby any desiredadjustment of the electrode longitudinally within the glass tube maybeaccomplished. A locknut 1O screws onto the stem of said electrode forthe purpose of locking it after adjustment. The stem 11 of the electrode7 is provided with a channel 12, running longitudinally therethrough andopening at its inner end into the interior of the glass tube, the outeropening 13 of said channel enabling the air to be withdrawn from theglass tube therethrough, so as to attain nearly a perfect vacuum withinthe tube. After the exhaustion of the air a needle-point valve 14 .isscrewed into the end of the stem of the electrode against the seat 15 insaid channel, thereby closing the channel and maintaining the vacuum.The stem 11 of the electrode 7 is also externally threaded, so that itmaybe screwed through its contact-terminal to effect a perfectadjustment of the electrode, and

after adjustment it is secured by the locknut 16 thereon.

By reason of the adjustment of the electrodes the distance between theiradjacent faces within the glass tube may be regulated to tively. Alsoconnected with said bindingposts are the circuit-wires 23 and 24, inwhich is included a battery 25 and a relay-magnet 26. This circuit isnormally opened at the coherer.

When an electrical impulse is received at the receiving-station, thewave-train is taken up by the aerials and passed along the conductors 22to the coherer, operating to cohere the filings in the receiver andclose the relay-circuit between the electrodes. In said relay-circuitmay be placed any suitable instrument (not, shown) for recording thepulsations. Upon the closing of the relay-circuit the armature 27 isattracted to close at point 28 the auxiliary circuit 29, including thebattery 30 and the electrical tapper 31, the hammer 32 of which isoperated to strike the end of the screw 14 in the stem of electrode 7and decohere the filings, thereby opening the relay-circuitvas soon asthe impulse is received.

It will now be understood that the impulses received through the aerialscause the closing of the relay-circuit and through said relay theclosing of the auxiliary circuit, operating the tapper to immediatelyopen the relay circuit at the coherer, whereby the dots and dashes orother forms of signals sent are reproduced in the receiving instrument.

A coherer of this character may be easily evacuated and perfectlysealed, and by means of the adjustable feature of the electrodes thecoherer may be regulated according to the tension or volume of theimpulses.

By reason of the contact-jaws 17, adapted to receive between them thecontact-terminals of the electrodes, a coherer may be readily slippedinto said jaws to place it in circuit and quickly and easily removedwithout detaching any of the conductors, making it possible to changecoherers while a signal is being received without losing any materialpart of the message.

Having thus fully set forth my'invention, what I claim as new, anddesire to secure by Letters Patent, is-

1. In a coherer for wireless signaling, the combination with suitablereceiving-conductors, ofa coherer comprising a tube of glass, or othernon-conducting material, non-conducting caps fitted to the ends of saidtube,

contact-terminals fitting into said caps, electrodes having threadedstems screwed through said terminals, the inner ends of said electrodesstanding opposed to each other within said tube, metallic'filingsoccupying the space within the tube between said electrodes,contact-jaws embracing said contact-terminals and connected with asource of electric energy.

2. In a coherer for wireless signaling, the combination with areceiving-conductor, of a coherer connected electrically therewith, saidcoherer comprising a non-conducting tube, caps fitted to the ends ofsaid tube, electrodes passing from the tube through the caps, arelay-circuit connected with said coherer, and an electrical tapperoperated by said relaycircuit adapted to'strike directly upon theprojecting end of one of said electrodes.

3. A coherer for wireless signaling comprising a non-conducting tube,caps fitted to the end of said tube, contact-terminals upon said caps,electrodes screwed through said terminals, metal filings between theends of the electrodes within said tube, the stem of one of theelectrodes having a longitudinal channel therethrough communicating withthe interior and exterior of the tube whereby airmay be exhausted fromthe tube, and means for closing the channel in the electrode after theexhaustion of air.

4. In a coherer, the combination of a suitable base, contact-jawsmounted upon said base, having parallel contact-faces, conductorsconnected electrically with said jaws, a relay-circuit including thereina source of electric energy, the terminals of said circuit being alsoconnected electricallywith said jaws, a coherer provided with suitableelectrodes, tapped contact terminals through which said electrodes arescrewed, said contact-terminals having squared portions adapted to fitbetween the contact-faces of the jaws, whereby the coherer may be placedin and removed from said jaws without disconnecting any of thecircuit-wires.

In testimony whereof I sign this specification in the presence of twowitnesses.

THOMAS E. CLARK.

Witnesses:

E. S. WHEELER, M. C. PooLE.

